ATLANTA -- With the start of Spring Training less than a month away, MLB.com is taking a look at what the Braves' roster might look like on Opening Day. Next up is the bullpen.
The most influential newcomer to the Braves' bullpen may prove to be Darren O'Day, the veteran reliever who spent last season's final months restricted to bystander status as he recovered from the left hamstring surgery that preceded last summer's trade from Baltimore to Atlanta.
"Everyone was wondering who the guy in the corner [of the clubhouse] was eating all the food," O'Day said. "That was me. But it was really cool. I was really grateful I got to be around the team."
A suburban Atlanta resident, O'Day got a feel for the Braves organization and his teammates as he was present for each of the team's home games following the July 31 trade. The 36-year-old reliever has been a regular visitor to SunTrust Park this offseason, and he has tested his repaired left hamstring while working out with Mike Foltynewicz and Charlie Culberson.
"I've been working with the young bucks, hanging with them and doing all the things they do, so I would think I'm healthy," O'Day said.

Though he has not yet thrown a pitch for the Braves, O'Day seems destined to establish himself as the veteran leader of the club's relatively inexperienced relief corps. More importantly, he wants to prove he is still worthy to be considered among the game's most reliable relievers.
O'Day earned his four-year, $31 million deal after posting a 1.92 ERA over the 273 appearances made from 2012-15. Though he's posted a more modest 3.56 ERA over the past three seasons, he's struck out 31.1 percent of the batters faced -- the 12th-best percentage among American League pitchers with at least 100 innings pitched.
"I think if Spring Training started today, I'd be ready to go," O'Day said. "I'm excited to contribute and help this bullpen and this pitching staff."
O'Day will be among the group of relievers used ahead of Arodys Vizcaino and A.J. Minter, who served in the closer's role while Vizcaino's bothersome shoulder sidelined him for much of the second half last season.
Here's a look at the top candidates for what will likely again be an eight-man Braves bullpen.
Closer candidates
Having had the opportunity to rest over the past few months, Vizcaino will come to Spring Training without any restrictions. But there is reason to be concerned about the veteran right-hander's ability to stay healthy while handling a normal workload. His availability in late September and during the postseason was a product of an expanded roster and the scheduled days off between playoff games.

Vizcaino was effective last year, posting a 2.11 ERA over 38 1/3 innings and converting 16 of 18 save opportunities. Per Statcast™, his average four-seam velocity (97.4 mph) was down just a tick from his 97.9 mph average in 2017. An MRI scan in October once again showed no structural damage in his inflamed right shoulder, but it remains to be seen whether Vizcaino can stay healthy.
Given those concerns, the Braves may opt to open the season with Minter as closer. The southpaw displayed his tremendous potential when he struck out 43.3 percent of the batters he faced while making the first 16 appearances of his career in 2017. The percentage dropped to 26.5 last year, which he blamed on attempting to be too fine on the corners during much of the season's first two months.
Minter posted a 2.18 ERA as he struck out 36.4 percent of the batters faced in June and July. His promising stretch was halted by the lower-back discomfort he battled throughout most of August. The changeup that he used more frequently in September could prove to be a valuable weapon as he attempts to regain the dominant form flashed in 2017.

With just 14 appearances under his belt, Chad Sobotka won't be given the closer's role. But he certainly looked like a future candidate when he came out of nowhere to allow just three runs over 14 1/3 innings. The big right-hander struck out eight of the last 15 batters he faced during the regular season and earned a spot on the National League Division Series roster.
Potentially valuable assets 
When the Braves excluded Dan Winkler, Shane Carle and Jesse Biddle from their NLDS roster, they acknowledged they likely wouldn't have won the division without the contributions they made before hitting a wall during what was the first full season for each.
Winkler posted a 0.74 ERA through his first 26 appearances. If his twice-repaired right elbow cooperates, he may again provide value in the middle innings. Carle produced a 2.58 ERA over 42 appearances made through the end of July and then missed most of August because of arm fatigue he experienced again in September. Biddle produced reverse splits during the early portion of the season and then found consistent success against left-handers, as he posted a 1.83 ERA over a 34-appearance stretch from May 28-Aug. 31.
Veteran southpaws
Jonny Venters won the NL Comeback Player of the Year Award after he produced a 3.67 ERA over the 50 appearances made for Tampa Bay and Atlanta. He has undergone 3 1/2 Tommy John surgeries, and his stuff might not be quite as electric as it was when he inhabited the Braves' bullpen at the start of this decade. But opponents barreled just three percent of the balls put in play against him last year.

The only Braves pitchers to allow a lower barrel percentage were Minter (1.8) and Sam Freeman (2.4). Freeman breezed through a heavy early-season workload and then was reintroduced to the command issues that have plagued him throughout his career. The veteran lefty spent nearly all of August on the disabled list and then did not allow a run over 10 appearances in September.